Variable-geometry aircraft

ABSTRACT

A variable-sweep-back-wing aircraft, each wing of which is provided in the junction between its leading edge and the fuselage with a wing root member formed in two portions, namely a nib lying adjacent to the fuselage and an eyelid lying intermediate between the nib and the wing, the nib and the eyelid both being pivoted to the wing about a common pivot which is parallel to the main wing pivot, and each being movable relatively to the wing and to the other, the nib and the eyelid together forming a continuation of the leading edge of the wing when the wing is in its fully-swept-back position, and the nib and the eyelid both lying wholly within the fuselage contour when the wing is in its outspread position of minimum sweep-back. The nib is also pivoted to the fuselage at a point spaced from its common pivot to the wing, by means of a pivot pin slidable in a track in the fuselage. During forward pivotal movement of the wing from its fully-swept-back position towards its outspread position, the initial movement of the wing causes the eyelid to pivot as one with the wing, while the nib is pivoted relatively to the wing and to the fuselage by the movement of the wing so as to partially enter the fuselage, while during continued pivotal movement of the wing in the same direction both the nib and the eyelid are carried into the fuselage by virtue of their connection to the wing.

United States Patent [191 Rhodes et al.

[54] VARIABLE-GEOMETRY AIRCRAFT [75] Inventors: Arthur Neville Rhodes;Denis Edward Blackburn, both of Fulwood, Preston, England [73] Assignee:British Aircraft Corporation Limited, London, England [22] Filed: May25, 1970 [21] Appl. No.: 51,400

[30] Foreign Application Priority Data May 27, 1969 Great Britain..26,8l3/69 [52] US. Cl. ..244/49, 244/39, 244/46 [51] Int. Cl ..B64c3/56 [58] Field of Search ..244/7 A, 39, 46, 244/49, 17.27

[56] References Cited UNITED STATES PATENTS 3,104,082 9/1963 Polhamus..244/49 3,510,088 5/1970 Bird ..244/46 FOREIGN PATENTS OR APPLICATIONS1,909,835 4/1968 Germany ..156/46 R Primary Examiner-Benjamin A.Borchelt Assistant Examiner-J. V. Doramus AttorneyCushman, Darby &Cushman May 22, 1973 [57] ABSTRACT A variable-sweep-back-wing aircraft,each wing of which is provided in the junction between its leading edgeand the fuselage with a wing root member formed in two portions, namelya nib lying adjacent to the fuselage and an eyelid lying intermediatebetween the nib and the wing, the nib and the eyelid both being pivotedto the wing about a common pivot which is parallel to the main wingpivot, and each being movable relatively to the wing and to the other,the nib and the eyelid together forming a continuation of the leadingedge of the wing when the wing is in its fullyswept-back position, andthe nib and the eyelid both lying wholly within the fuselage contourwhen the wing is in its outspread position of minimum sweepback. The nibis also pivoted to the fuselage at a point spaced from its common pivotto the wing, by means of a pivot pin slidable in a track in thefuselage. During forward pivotal movement of the wing from itsfully-swept-back position towards its outspread position, the initialmovement of the wing causes the eyelid to pivot as one with the wing,while the nib is pivoted relatively to the wing and to the fuselage bythe movement of the wing so as to partially enter the fuselage, whileduring continued pivotal movement of the wing in the same direction boththe nib and the eyelid are carried into the fuselage by virtue of theirconnection to the wing.

4 Claims, 8 Drawing Figures Patented May 22, 1973 5 Sheets-Sheet 1INVENTORS Am'uua N Quota b BY mu. 2 BucxBwm WW b ORNEYS Patented May 22,1973 5 Sheets-Sheet 5 INVENTORS Alumna N Ruouzs b B u BY :Nls E. LAQKQan ATZ'ORNEYS Patented May 22, 1973 3 3,734,431

5 Sheets-Sheet 5 INVENTORS ARTHUR N. Rnonen DEN| E BucmuRN m baw w ('Ml/wvw A] IURNLYS 1 VARIABLE-GEOMETRY AIRCRAFT The present inventionrelates to variable-geometry aircraft having variable sweep-back wings,and specifically to those aircraft having a leading edge root member oneach wing movable with respect to the wing so that when the wings are ina highly swept-back configuration the movable root members form acontinuation of the wing leading edges, and when the wings are in anoutspread configuration the movable root members lie within the fuselagecontour.

According to the present invention an aircraft of the type described hasassociated with each wing a leading edge root member formed in twoportions, each movable relatively to the wing and to the other portion,said movable portions together forming a continuation of the wingleading edge when the wing is highly sweptback and both lying whollywithin the fuselage contour when the wing is in an outspread position ofreduced sweep-back.

In one arrangement, the said portions are of such a configuration andare so located and interconnected that on initial forward movement ofthe wing from the highly swept-back position the said portions move asone, and on continued forward movement of the wing towards the minimumsweep-back position the said portions move angularly relatively to oneanother into overlapping relationship within the fuselage contour.

During this latter stage of movement of the wing, one of the rootmembers may move relatively to the wing whilst the other moves as onewith the wing relatively to the other member.

Preferably the said root portions are pivoted to the wing at the samepoint, and one of said portions is pivoted to the fuselage by means of apivot constrained to move along a fixed path within the fuselage.

Preferably also, the movement of the said portions is effected by thewing sweep movements only, and without the assistance of any additionaljacks, motors or the like.

The invention may be carried into practice in various ways, but onespecific embodiment will now be described by way of example only andwith reference to the accompanying drawings, in which:

FIG. 1 shows a plan view of an aircraft wing root incorporating theinvention with the wing in a position of maximum sweep-back,

FIG. 2 is a similar view with the wing in an intermediate sweep-backposition,

FIG. 3 is a similar view but with the wing in a position of minimumsweep-back,

FIG. 4 is a view on Arrow V of FIG. 1 showing in outline the profile ofsections taken on lines B-B, C-C, DD, and E-E of that Figure,

FIG. 5 is a view on Arrow V of FIG. 2 showing in outline the profile ofsections taken on lines BB, C-C,

DD and EE of that Figure,

FIG. 6 is a view on Arrow VI of FIG. 3 showing in outline the profile ofsections taken on lines AA, BB, C-C, DD and 15-13 of that Figure,

FIG. 7 is a composite sectional view incorporating sections taken online 1-] of FIGS. 1, 2 and 3, and

FIG. 8 is a plan of an aircraft embodying the wing root construction ofFIGS. 1 to 7 in both wings, the port wing being shown in thefully-swept-back wing position and the starboard wing in the outspreadposition.

The section lines BB, C-C, DD, B45 and JJ are located at identicalstations in each of FIGS. 1, 2 and 3.

For clarity the invention is described and illustrated in FIGS. 1 to 7with reference to only one wing (the port wing) of the aircraft shown inFIG. 8; it is of course applied similarly to both wings.

Referring initially to FIGS. 1, 2, 3, and 8 a variable sweep-back wingaircraft has a fuselage 1, the port side profile of which is shown at 2in FIGS. 1 to 3, and wings 3, the leading edges of which are shown at 4.The port wing 3 is arranged to swing about a pivot 5 (FIGS. 2 and 3)mounted outboard of the fuselage l on a structure extending from thefuselage and smoothly covered by fairing 6. The pivot 5 may, as analternative, be mounted within the fuselage. The upper fuselage skin iscut away at 7 in the vicinity of the wing root leading edge.

The wing 3 is provided with a first leading edge root portion 8(hereinafter termed the nib) and a second leading edge root portion 9(hereinafter termed the eyelid), both portions being pivoted to the wing3 about a generally vertical pivot axis at 10. The nib 8 is alsoconnected to the fuselage 1 by means of a pivot member l l which isitself constrained to move bodily along a track 12 mounted in thefuselage.

The nib 8 and the eyelid 9 are movable about the pivot 10 bothrelatively to the wing and relatively to each other. The pivot 10, beingmounted on the wing, is constrained to move in an are 20 as the wing 3swings about its pivot 5.

The nib 8 and the eyelid 9 are both of generally partaerofoil shape incross-section, having leading edges 13 and 14, respectively. Both thenib 8 and the eyelid 9 have at least partially hollow interiors. That ofthe eyelid 9 allows the inboard leading edge 15 of the wing to passthrough it (see FIG. 2) whilst that of the nib 8 allows both the eyelid9 and the inboard leading edge 15 of the wing to enter (see FIG. 3).

The eyelid 9 is spring-biased by spring means 9A so as to tend to remainin the position with respect to the nib 8 shown in FIG. 1 untilpositively urged to a different position.

As shown in FIG. 1, when the wing 3 is in a position of maximumsweep-back the inboard flank 18 of the wing remains just within outboardflank 16 of the eyelid 9 whilst the inboard flank 17 of the eyelid 9remains just within the outboard or trailing flank 19 of the nib 8. Alsoin this wing position the inboard edge 30 of the nib 8 remains justwithin the line of the fuselage skin cut-away 7.

To reach an outspread position, assuming the wing 3 to be initially'inthe position of FIG. 1, that is to say in the position of maximumsweep-back, the wing is moved in a clockwise direction, as illustrated,about its pivot 5. The pivot 10 thus moves along arc 20 and, since boththe nib 8 and the eyelid 9 are pivoted at 10 to the wing, they are bothmoved generally inboard and forward, but remain in the same positionrelative to one anotherby virtue of the spring means 9A until theposition of FIG. 2 is reached. In this position, which is anintermediate sweep-back position, the inboard leading edge 15 and theinboard flank 18 of the wing extend entirely through the eyelid 9 andinto the nib 8. The nib 8 has now pivoted in an anticlockwise direction(as shown) about its fuselage pivot 11 which has moved generally forwardalong its track 12 to accommodate the arcuate movement of the pivot 10.

Although the nib 8 rotates as described, the positioning of the track 12is such that the leading edge 13 of the nib always passes through thefuselage skin at the same point 21. This arrangement simplifies thedesign of the fuselage/nib seals.

In FIG. 2 the wing leading edge 4 is shown as just contacting theoutboard interior corner of the leading edge 14 of the eyelid 9. As thewing further rotates about its pivot 5, the eyelid 9 is urged away fromits initial position with respect to the nib 8 by this contact with therotating wing, and is carried by the wing leading edge 4 generallyinboard into the interior of the nib 8. The pivot continues to movealong its arcuate path 20.

FIG. 3 shows the wing 3 in its position of minimum sweep. In thisposition the pivot 10 has reached its furthest inboard location alongthe path 20, the leading edge 13 of the nib 8 lies along the fuselagecontour 2, and what was the outboard tip of the nib leading edge 13 hasengaged the leading edge 4 of the wing 3 at 22. The eyelid 9 has beencarried by the wing 3 well into the interior of the nib 8 andsimultaneously the fuselage pivot point 1 1 of the nib has movedgenerally rearwards along its track 12.

It will be appreciated that these rotary movements of the eyelid 9 andnib 8 from their positions of FIG. 1 into their positions of FIG. 3 arecaused entirely by their mechanically coupling with the forwardlyswinging wing, and not by any auxiliary motors, jacks, etc.

The movement of the wing in the rearward direction from this outspreadposition to a position of increased sweep-back causes movements of thenib and the eyelid 9 which are in the exact opposite sequence to thatdescribed.

FIGS. 4, 5 and 6, being views on Arrows IV, V and VI of FIGS. 1, 2 and3, respectively and on which profile lines of the various sections AA,B-B, C-C, etc. have been superimposed, serve to show how the nib 8, theeyelid 9 and the wing 3 merge to provide a measure of leading edge droopwhich feature is found to be aerodynamically desirable on mostswept-wing aircraft. These Figures also show how the aerofoil contoursat various sections can be arranged, by local modification, to fitclosely together to yield an effective wing root and fuselage junction.

FIG. 7, being a composite section taken on lines JJ of FIGS. 1, 2 and 3,illustrates the varying positions adopted by the nib 8 with respect tothe fuselage 1. This Figure also shows how, in the position of FIG. 3with the wing 3 in a position of minimum sweep-back, the upper surface23 of the nib 8 forms part of the fuselage contour and how it mergeswith the cut-away skin line 7.

An effective but simple flexible seal 24 is affixed to the lip of thelower fuselage skin to contact the underside of the nib 8 in its variouspositions.

The starboard wing 3 of the aircraft is also provided with a nib andeyelid construction which is similar to and arranged similarly to thatof the port wing, but is a mirror image thereof in plan.

An aircraft having variable-sweep-back wings as described andillustrated has the following advantages:

1. In the minimum sweep-back wing position the nib 8 and the eyelid 9lie within the fuselage contours. Thus the wing has an uninterruptedleading edge which is not shielded by leading edge portions fixed to thefuselage, permitting the use of full-span leading edge high liftdevices.

2. Elaborate, and therefore costly, seals between the nib 8 and thefuselage 1 are rendered unnecessary.

3. The nib 8 andthe eyelid 9 can conveniently conform to locallymodified wing root aerofoil sections such as the drooped leading edgeillustrated.

4. The nib 8 and the eyelid 9 require no separate actuation gear and areoperated entirely by wing sweep movements.

Although the wing leading edge 4 is shown in FIGS. 1 and 2 to have akink 24, this is necessary only in the exact configuration illustrated.It would not be necessary, or even desirable, in alternativeconfigurations according to the invention.

As illustrated, the plane of wing sweep movement is parallel to thefuselage fore-and-aft axis, that is to say the axes of the pivots 5 arevertical with respect to the fuselage axis (assumed horizontal) andparallel to each other. The invention is also applicable to embodimentswhere the plane of wing sweep movement of each wing is angled to thefuselage fore-and-aft axis and the axes of the pivots 5 are canted withrespect to each other and to the fuselage.

However, in all cases the nib 8 must pivot in a plane perpendicular tothe axis of the respective wing pivot 5.

What we claim as our invention and desire to secure by Letters Patentis:

1. An aircraft having a fuselage with variable-sweepback wings, eachmovable in an associated plane of wing-sweep movement, each wing havinga main wing portion pivoted to the fuselage and a two-portion rootmember at its leading edge, said root member being movable with respectto the main wing portion and to the fuselage so that when the wing is ina fully sweptback configuration the two root portions of the root memberextend outside the fuselage to form together a continuation of theleading of the wing at its root, and when the wing is in a fullyoutspread configuration the said root portions lie within the fuselagecontour, first pivot means pivoting a first of said root portions to thefuselage, and second pivot means pivoting both the said first rootportion and the second of said root portions to the main wing portion,both said pivot means allow ing pivotal movement about pivotal axesextending generally normally to the associated plane of wing sweepmovement, the two root portions being of partaerofoil shape with atleast partially hollow interiors, the interior of the said first rootportion being such as to allow the said second root portion and a partof the leading edge of the main wing portion to enter said interior, andthe interior of the said second root portion being such as to allow apart of the leading edge of the main wing portion to extend through it,there being provided means for causing sweep movement of each main wingportions, and biasing means acting between the said first and secondroot portions to bias them pivotally towards their said positionsextending outside the Y fuselage, and engagement means for causingengagement between the said second root portion and the main wingportion such that on initial forward sweep movement of the main wingportion from the fully swept-back configuration the said movement of themain wing portion acting through said second pivot means causes the saidfirst and second root portions to move as one into the interior of thefuselage contour, pivoting relatively to the fuselage about said firstpivot means and relatively to the main wing portion about said secondpivot means, and during further forward sweep movement of the main wingportion towards the fully-outspread configuration the said engagementmeans engages the said second root portion with the main wing portion tocause the said second root portion to move as one with the main wingportion and relatively to the said first root portion against the actionof the biasing means.

2. An aircraft according to claim 1 wherein the said first pivot meanscomprises a pivot member and a track in which the pivot member isslidably engaged for sliding movement along the track, the track beingso located in the fuselage that the leading edge of the said first rootportion intersects the fuselage contour at substantially the samelocation throughout the wing sweep movement.

3. An aircraft according to claim 1 wherein the biasing means comprisesa spring acting directly between the said first and second rootportions.

4. An aircraft according to claim 1 wherein the engagement meanscomprises a member located in the interior of the second root portionand a co-operating member located on the exterior of the main wingportlon.

1. An aircraft having a fuselage with variable-sweep-back wings, eachmovable in an associated plane of wing-sweep movement, each wing havinga main wing portion pivoted to the fuselage and a two-portion rootmember at its leading edge, said root member being movable with respectto the main wing portion and to the fuselage so that when the wing is ina fully swept-back configuration the two root portions of the rootmember extend outside the fuselage to form together a continuation ofthe leading of the wing at its root, and when the wing is in a fullyoutspread configuration the said root portions lie within the fuselagecontour, first pivot means pivoting a first of said root portions to thefuselage, and second pivot means pivoting both the said first rootportion and the second of said root portions to the main wing portion,both said pivot means allowing pivotal movement about pivotal axesextending generally normally to the associated plane of wing sweepmovement, the two root portions being of part-aerofoil shape with atleast partially hollow interiors, the interior of the said first rootportion being such as to allow the said second root portion and a partof the leading edge of the main wing portion to enter said interior, andthe interior of the said second root portion being such as to allow apart of the leading edge of the main wing portion to extend through it,there being provided means for causing sweep movement of each main wingportions, and biasing means acting between the said first and secondroot portions to bias them pivotally towards their said positionsextending outside the fuselage, and engagement means for causingengagement between the said second root portion and the main wingportion such that on initial forward sweep movement of the main wingportion from the fully swept-back configuration the said movement of themain wing portion acting through said second pivot means causes the saidfirst and second root portions to move as one into the interior of thefuselage contour, pivoting relatively to the fuselage about said firstpivot means and relatively to the main wing portion about said secondpivot means, and during further forward sweep movement of the main wingportion towards the fullyoutspread configuration the said engagementmeans engages the said second root portion with the main wing portion tocause the said second root portion to move as one with the main wingportion and relatively to the said first root portion against the actionof thE biasing means.
 2. An aircraft according to claim 1 wherein thesaid first pivot means comprises a pivot member and a track in which thepivot member is slidably engaged for sliding movement along the track,the track being so located in the fuselage that the leading edge of thesaid first root portion intersects the fuselage contour at substantiallythe same location throughout the wing sweep movement.
 3. An aircraftaccording to claim 1 wherein the biasing means comprises a spring actingdirectly between the said first and second root portions.
 4. An aircraftaccording to claim 1 wherein the engagement means comprises a memberlocated in the interior of the second root portion and a co-operatingmember located on the exterior of the main wing portion.